1. Field of the Invention
This invention relates to a process and apparatus for removing dust and other particles which are present as a result of slinging a slinging mass into the free space between the wall of the casting ladle and an inserted template to build up the lining. More especially, this invention relates to an apparatus for removing residual dust, dirt and debris, especailly fine sand particles and the like, which are whirled up during a slinging process wherein a slinging mass is applied to the walls of a casting by slinging the mass vertically from above into a free space between the inner walls of the casting ladle and a defining template spaced therefrom.
2. Discussion of the Prior Art
The preparation of refractory linings for vessels to be employed in metals refinery is known. A device for the production of such a refractory ling is disclosed in the British Pat. No. 1,326,097, or the U.S. Pat. No. 3,872,912 which technique is specifically referred to for better understanding. According to some of the known processes a template is disposed opposite the walls of the vessel to be lined so as to define the region is which the liner is to be formed. The slinging mass is slung using known slinging apparatuses such as those disclosed in German Pat. Nos. 1,235,522 and 2,004,429, corresponding to U.S. Pat. No. 3,872,912. Other slinging machines are disclosed in German Pat. Nos. 1,247,561 and 1,289,963. The slinging machine disclosed in British Pat. No. 1,326,097 can also be employed as well as the device disclosed in German Offenlegungsschrift No. 1,483,584. According to the state of the art the lining of casting ladles is carried out wherein the refractory mass is slung in quick succession and at high speed by the use of the slinger head of the slinging machine into the free space between the wall of the ladle and a template inserted therein.
The mass employed includes a sand composition. Slinging of the slinging mass including the slinger sand causes a dust nuisance for operating personnel owing to the high proportion of fine grains in the sand and the air introduced during the slinging operation which is usually at a high velocity. This nuisance is particularly acute in the region surrounding the free space between the refractory wall and the template. Because of these nuisances it has heretofore been proposed to add moisture or oil to the dry masses. Other methods for reducing the dust nuisance have included sucking off the collected dust upwards from the free space to decrease the dust nuisance. However, to effectively decrease dust nuisance it has been necessary to provide a suction hood over the point where the dust forms. This known suction procedure is not only expensive and cumbersome but has proven to be unsatisfactory even with high suction performance as the formation of dust still leads to hinderances and nuisances to operating personnel.
It is therefore an object of this invention to provide a process and apparatus which guarantee good and effective dust removal from the region surrounding the free space between the walls of the refractory vessel and the template. It has become an object of this invention, moreover, to provide an apparatus which can be effectively employed which does not require the use of a hood disposed over the free space. Moreover, it has become desirable to provide a process and apparatus for effective dust removal whereby the dust removal can be effective with substantial unimpairment to the slinging operation itself.